In recent years, a stereoscopic display device which stereoscopically displays a video image is becoming widely used. A plurality of images seen from a plurality of viewpoints, for example, an image for the left eye and an image for the right eye, are displayed on the stereoscopic display device. A viewer sees the image for the right eye through the right eye and sees the image for the left eye through the left eye, so that the viewer sees a displayed video image stereoscopically.
By the way, the resolution of the image for the right eye and the resolution of the image for the left eye are not necessarily the same. For example, if one image is captured by a main camera and the other image is captured by a sub-camera, images having different resolutions may be acquired. However, when encoding the acquired images, the resolutions of all images must be the same depending on the encoding standard. Therefore, at least one of the images for the right eye and the left eye needs to be scaled.
When the image having a high resolution is reduced according to the image having a low resolution, there is a problem that a feeling of fineness is lost. On the other hand, when the image having a low resolution is enlarged according to the image having a high resolution, there is a problem that the difference between the image qualities of the two images becomes conspicuous.